/**
 * Copyright 2009-2020 the original author or authors.
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.ibatis.session;

import org.apache.ibatis.cursor.Cursor;
import org.apache.ibatis.executor.BatchResult;

import java.io.Closeable;
import java.sql.Connection;
import java.util.List;
import java.util.Map;

/**
 * The primary Java interface for working with MyBatis.
 * Through this interface you can execute commands, get mappers and manage transactions.
 *
 * @author Clinton Begin
 */
public interface SqlSession extends Closeable {

	/**
	 * Retrieve a single row mapped from the statement key.
	 * @param <T> the returned object type
	 * @param statement
	 *          the statement
	 * @return Mapped object
	 */
	<T> T selectOne(String statement);

	/**
	 * Retrieve a single row mapped from the statement key and parameter.
	 * @param <T> the returned object type
	 * @param statement Unique identifier matching the statement to use.
	 * @param parameter A parameter object to pass to the statement.
	 * @return Mapped object
	 */
	<T> T selectOne(String statement, Object parameter);

	/**
	 * Retrieve a list of mapped objects from the statement key.
	 * @param <E> the returned list element type
	 * @param statement Unique identifier matching the statement to use.
	 * @return List of mapped object
	 */
	<E> List<E> selectList(String statement);

	/**
	 * Retrieve a list of mapped objects from the statement key and parameter.
	 * @param <E> the returned list element type
	 * @param statement Unique identifier matching the statement to use.
	 * @param parameter A parameter object to pass to the statement.
	 * @return List of mapped object
	 */
	<E> List<E> selectList(String statement, Object parameter);

	/**
	 * Retrieve a list of mapped objects from the statement key and parameter,
	 * within the specified row bounds.
	 * @param <E> the returned list element type
	 * @param statement Unique identifier matching the statement to use.
	 * @param parameter A parameter object to pass to the statement.
	 * @param rowBounds  Bounds to limit object retrieval
	 * @return List of mapped object
	 */
	<E> List<E> selectList(String statement, Object parameter, RowBounds rowBounds);

	/**
	 * The selectMap is a special case in that it is designed to convert a list
	 * of results into a Map based on one of the properties in the resulting
	 * objects.
	 * Eg. Return a of Map[Integer,Author] for selectMap("selectAuthors","id")
	 * @param <K> the returned Map keys type
	 * @param <V> the returned Map values type
	 * @param statement Unique identifier matching the statement to use.
	 * @param mapKey The property to use as key for each value in the list.
	 * @return Map containing key pair data.
	 */
	<K, V> Map<K, V> selectMap(String statement, String mapKey);

	/**
	 * The selectMap is a special case in that it is designed to convert a list
	 * of results into a Map based on one of the properties in the resulting
	 * objects.
	 * @param <K> the returned Map keys type
	 * @param <V> the returned Map values type
	 * @param statement Unique identifier matching the statement to use.
	 * @param parameter A parameter object to pass to the statement.
	 * @param mapKey The property to use as key for each value in the list.
	 * @return Map containing key pair data.
	 */
	<K, V> Map<K, V> selectMap(String statement, Object parameter, String mapKey);

	/**
	 * The selectMap is a special case in that it is designed to convert a list
	 * of results into a Map based on one of the properties in the resulting
	 * objects.
	 * @param <K> the returned Map keys type
	 * @param <V> the returned Map values type
	 * @param statement Unique identifier matching the statement to use.
	 * @param parameter A parameter object to pass to the statement.
	 * @param mapKey The property to use as key for each value in the list.
	 * @param rowBounds  Bounds to limit object retrieval
	 * @return Map containing key pair data.
	 */
	<K, V> Map<K, V> selectMap(String statement, Object parameter, String mapKey, RowBounds rowBounds);

	/**
	 * A Cursor offers the same results as a List, except it fetches data lazily using an Iterator.
	 * @param <T> the returned cursor element type.
	 * @param statement Unique identifier matching the statement to use.
	 * @return Cursor of mapped objects
	 */
	<T> Cursor<T> selectCursor(String statement);

	/**
	 * A Cursor offers the same results as a List, except it fetches data lazily using an Iterator.
	 * @param <T> the returned cursor element type.
	 * @param statement Unique identifier matching the statement to use.
	 * @param parameter A parameter object to pass to the statement.
	 * @return Cursor of mapped objects
	 */
	<T> Cursor<T> selectCursor(String statement, Object parameter);

	/**
	 * A Cursor offers the same results as a List, except it fetches data lazily using an Iterator.
	 * @param <T> the returned cursor element type.
	 * @param statement Unique identifier matching the statement to use.
	 * @param parameter A parameter object to pass to the statement.
	 * @param rowBounds  Bounds to limit object retrieval
	 * @return Cursor of mapped objects
	 */
	<T> Cursor<T> selectCursor(String statement, Object parameter, RowBounds rowBounds);

	/**
	 * Retrieve a single row mapped from the statement key and parameter
	 * using a {@code ResultHandler}.
	 * @param statement Unique identifier matching the statement to use.
	 * @param parameter A parameter object to pass to the statement.
	 * @param handler ResultHandler that will handle each retrieved row
	 */
	void select(String statement, Object parameter, ResultHandler handler);

	/**
	 * Retrieve a single row mapped from the statement
	 * using a {@code ResultHandler}.
	 * @param statement Unique identifier matching the statement to use.
	 * @param handler ResultHandler that will handle each retrieved row
	 */
	void select(String statement, ResultHandler handler);

	/**
	 * Retrieve a single row mapped from the statement key and parameter using a {@code ResultHandler} and
	 * {@code RowBounds}.
	 *
	 * @param statement
	 *          Unique identifier matching the statement to use.
	 * @param parameter
	 *          the parameter
	 * @param rowBounds
	 *          RowBound instance to limit the query results
	 * @param handler
	 *          ResultHandler that will handle each retrieved row
	 */
	void select(String statement, Object parameter, RowBounds rowBounds, ResultHandler handler);

	/**
	 * Execute an insert statement.
	 * @param statement Unique identifier matching the statement to execute.
	 * @return int The number of rows affected by the insert.
	 */
	int insert(String statement);

	/**
	 * Execute an insert statement with the given parameter object. Any generated
	 * autoincrement values or selectKey entries will modify the given parameter
	 * object properties. Only the number of rows affected will be returned.
	 * @param statement Unique identifier matching the statement to execute.
	 * @param parameter A parameter object to pass to the statement.
	 * @return int The number of rows affected by the insert.
	 */
	int insert(String statement, Object parameter);

	/**
	 * Execute an update statement. The number of rows affected will be returned.
	 * @param statement Unique identifier matching the statement to execute.
	 * @return int The number of rows affected by the update.
	 */
	int update(String statement);

	/**
	 * Execute an update statement. The number of rows affected will be returned.
	 * @param statement Unique identifier matching the statement to execute.
	 * @param parameter A parameter object to pass to the statement.
	 * @return int The number of rows affected by the update.
	 */
	int update(String statement, Object parameter);

	/**
	 * Execute a delete statement. The number of rows affected will be returned.
	 * @param statement Unique identifier matching the statement to execute.
	 * @return int The number of rows affected by the delete.
	 */
	int delete(String statement);

	/**
	 * Execute a delete statement. The number of rows affected will be returned.
	 * @param statement Unique identifier matching the statement to execute.
	 * @param parameter A parameter object to pass to the statement.
	 * @return int The number of rows affected by the delete.
	 */
	int delete(String statement, Object parameter);

	/**
	 * Flushes batch statements and commits database connection.
	 * Note that database connection will not be committed if no updates/deletes/inserts were called.
	 * To force the commit call {@link SqlSession#commit(boolean)}
	 */
	void commit();

	/**
	 * Flushes batch statements and commits database connection.
	 * @param force forces connection commit
	 */
	void commit(boolean force);

	/**
	 * Discards pending batch statements and rolls database connection back.
	 * Note that database connection will not be rolled back if no updates/deletes/inserts were called.
	 * To force the rollback call {@link SqlSession#rollback(boolean)}
	 */
	void rollback();

	/**
	 * Discards pending batch statements and rolls database connection back.
	 * Note that database connection will not be rolled back if no updates/deletes/inserts were called.
	 * @param force forces connection rollback
	 */
	void rollback(boolean force);

	/**
	 * Flushes batch statements.
	 * @return BatchResult list of updated records
	 * @since 3.0.6
	 */
	List<BatchResult> flushStatements();

	/**
	 * Closes the session.
	 */
	@Override
	void close();

	/**
	 * Clears local session cache.
	 */
	void clearCache();

	/**
	 * Retrieves current configuration.
	 * @return Configuration
	 */
	Configuration getConfiguration();

	/**
	 * Retrieves a mapper.
	 * @param <T> the mapper type
	 * @param type Mapper interface class
	 * @return a mapper bound to this SqlSession
	 */
	<T> T getMapper(Class<T> type);

	/**
	 * Retrieves inner database connection.
	 * @return Connection
	 */
	Connection getConnection();
}
